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<html lang="en">

<head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
</head>

<body>
    <script>
        const arr = [{
            id: 1,
            name: "西瓜",
            state: true,
            price: 10,
            count: 1,
        }, {
            id: 2,
            name: "榴莲",
            state: false,
            price: 80,
            count: 2,
        }, {
            id: 3,
            name: "草莓",
            state: true,
            price: 20,
            count: 3,
        }, ];
        let result = arr
            .filter((item) => item.state)
            .reduce((amt, item) => amt += item.price * item.count, 0);
    </script>
</body>

</html>